1. The field of this invention
is oil well production and servicing.
2. Description of the Prior Art.
The Panhandle of Texas and many other oil fields produce paraffin-base oil, while while other fields produce asphalt-base oil. Paraffin-base oil causes a problem and is expensive to produce because the oil derived continues to release paraffin inside the wells' walls, adhering to tubing, rods, paddles, etc. A sticky, gummy, substance, known as paraffin rather quickly clogs the tubing, thus reducing the efficiency of the energy used for production.
When a well's temperature at oil formation is below 160 degrees fahrenheit, the well is subject to increased paraffin deposit problems. Wells in the Panhandle of Texas have a temperature ranging between 80-85 degrees Fahrenheit, which means that in such wells, a steady build-up of paraffin on the interior within the walls of the wells' tubing occurs as a result of such comparatively low temperatures, which affects the pumping equipment notwithstanding use of rotating paddles.
With the wearing of pump parts, the pump will no longer pump fluids into the above ground storage tanks. This requires the pulling of the pump to the surface to be overhauled or replaced with a pump that will lift properly.
When the pump piston and sucker rods attached thereto are now pulled by conventional practices from the pump's seat, which is initially precisely in the center of the tubing, in returning to the surface the pump piston does not remain in the center of the tubing but scrapes the sides of the interior wall of the tubing string while creating unequal deposits of paraffin on the tubing walls.
This occurs because when the pump has been pulled from its seat and dragged against the tubing wall to the surface, it changes direction as it moves and scrapes the sides of the tubing and paraffin deposit on the wall in some places, leaving a 1/2 inch thick accumulation in others. The bare tubing and 1/2" paraffin patches within the wall create a zig-zag, off-set puzzle which made re-entry of the pump against a maze of friction too great a risk for practical relible economic use.
Producers have ceased the practice of using standing valves, (those valves left in the tubing below the pump which retain the fluids in the tubing when the pump and rods are pulled). This, in turn, causes the fluids to flow back into the well. The reason usually offered for not using a standing valve is the great risk incurred in trying to re-run the pump and rods back into the tubing, as such a practice creates a build-up of paraffin in and on the pump that results in stoppage prior to achieving seating, whereupon the pump and rods must be pulled again. In addition, the tubing must be pulled and steam-cleaned.
The dumping of the fluids back into a well's pay formation is a prime factor in reducing the well's capacity to produce at maximum level and causes much expense later in cleaning the formation with heat, chemicals, or tools. It requires a significant amount of energy to refill the tubing, and the delay in the resumption of production adds to the total loss. Accordingly, by conventional practices, the repair or changing of the pump in order to resume production causes much waste of time, energy, and pre-depletion of the tubing.